1. Field of the Invention
The present invention generally relates to a radiation sensing system and, more particularly, but not by way of limitation, to a radiation sensing system with improved resistance to damage from radiation consequential to prolonged operation.
2. Description of the Related Art
Radiation sensing systems are well known and are used when it is necessary to detect various bands of wavelength across the electromagnetic spectrum. As such, radiation sensing systems are employed to detect ultraviolet radiation associated with drinking water disinfecting units.
Generally, irradiating water with sufficient amounts of ultraviolet light will disinfect water for human consumption by eliminating microorganisms from the water. Commercially available drinking water disinfecting units typically employ ultraviolet light emitting lamps disposed within a passageway whereby water flowing through the passageway is disinfected by designated amounts of ultraviolet light emitted from the lamps.
Radiation sensing systems are often incorporated in drinking water disinfecting units to monitor the level of ultraviolet radiation emitted from the lamps, thereby enabling the overall efficiency of the water disinfection process to be assessed over a period of time. Unfortunately, however, subjecting radiation sensing systems to continuous and often highly increased radiation levels leads to progressive degradation and irreversible damage in that the radiation sensing system will no longer accurately detect ultraviolet light or may even completely fail.
Past attempts to mitigate potential damage from prolonged exposure to radiation have driven the overall cost of radiation sensing systems upward. As such, due to costs associated with repair or replacement, the use of current radiation sensing systems during the intended life span of a drinking water disinfecting unit is unreasonably expensive. For example, radiation sensing systems are unreasonably expensive in that such systems are often constructed entirely of stainless steel, which is well known to be relatively resistant to degradation from radiation. Moreover, radiation sensors within radiation sensing systems are independently and commercially available and are often expensive by design. In particular, well known "can" designs which house photodiodes are unreasonably costly. Costs associated with radiation sensors may also increase depending on the size, shape, and color of a photodiode filter.
Accordingly, there is a long felt need for a cost effective radiation sensing system with improved resistance to radiation damage.